But the call to register the Vector2f DependencyProperty called "Size" just crashes with the following stack trace (Unhandled exception at 0x00007FFBBAD278D0 (Noesis.dll) in EnscapeClient.exe: Fatal program exit requested.):

I am just trying to reproduce it here and it is working fine. I am able to register Vector2f and Vector3f dependency properties successfully. Could you please report this in the tracker and provide us a link to a minidump? That way we can easily understand what's going on.

By the way, Vector2f and Vector3f are suppose to be internal math classes, we plan to hide them in the future (and also remove internally their reflection metadata). So I recommend creating your own structs for your specific purpose. This is not going to happen soon but it will in the future as part of our commitment to reduce the API surface expose to clients.